1. Field of the Invention
This invention relates to a method and apparatus for separating image areas in facsimile machines, scanners, and other image processing equipment, and more particularly, to a method and apparatus for separating image regions by extracting features of graphic images and characters.
2. Description of the Related Art
A conventional picture processing apparatus as shown in the block diagram of FIG. 1 subjects picture data to dither processing. The apparatus includes a sample holder 10 for recording analog data input thereto and an A/D converter 20 for digitizing the data from the sample holder. The digital data is transmitted at a predetermined bit rate and then dithered by software.
Another example of a conventional apparatuses as shown in FIG. 2 includes a sample holder 10, a D/A converter 30 supplied with dither data from a data bus for conversion into an analog form, and a comparator 40 supplied with the analog data from the D/A converter 30 and input data for producing dithered data.
With these conventional picture processor apparatuses, graphic data and characters contained in picture data are indifferently dithered, and while graphic presentations are acceptable, the halftone processing causes the characters to appear dull and unclear.